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E. DQ BARRETT, OF NEW HAVEN, CONNECTICUT, ASSIGrNOIt` T0 HIMSELF AND JULI-US 'B. SAVAGE,

Letters Patent No. 60,822, dated January] I, 1867.

IMPROVED- DIES POE CUTTING SGREWS.

TO ALL WHOM-IT MAY CONCERN:

Be it known thatlI, E. D. BARRETT, of New Haven, in the countyvoi` New Haven, and State of Connecticut', have invented a new improvement in Adjusting Dies for ScrewCutting Machines; and I do hereby declare the following, when taken in connection with the accompanying drawings, and the letters of reference marked thereon, to be a. full, clear, andA exact description of the same,iand which said drawings constitute part of this specication, and represent, in`

Figure I, a side view of the cutter head of the machine, to which my improvement is especially adapted; and, in

Figure 2, an end view of the cutter head, showing the cutters as heretofore set; also my improvement thereon.

My inyentionconsists in the peculiar manner of adjusting the cutters, so as to commencctheir cut at different points on the screw,vor at diiferent inclination thereto; and to enable otherato construct and use my improvement, Iwill proceed to describethc same as illustrated in the accompanying drawings.

A is the bed of the machine; B the mandrel supported in bearings, C, and caused to revolve by the application of power to the pulley D. On the outer end oi' the mandrel are hung four levers, E E and F F, more or less,) their extreme outer ends forming holders for' the cutters e and y", as seen in iig. 2. On the mandrel is j placed an adjusting cone, GE, which, being forced under the inner ends of the levers, as seen in iig. l, closes the cutters upon therod upon which the screw is to be eut, and when drawn out the springs d open the cutters.

This construction of the machine is common and well known. Heretofore the cutters have been iixedj'in the levers, as seen in F, iig. 2. The only adjustment which could be given tothe cutters Was by means of the screws d; this would only adjust the diameter of the screw, so that when it was required to change the position of the cutting edge, the form of the cutter must be changed accordingly, a source of considerable inconvenience in .the use of thesemachines. -By my invention the cutter may be readily adjusted, as will be seen in iig. 2. The cutter end of the lever E is formed to receive the cutter e, and beside it a wedge, I. A-set-screw, I, adjusts the cutter etc the diameter of the screw required; the screw c operating the wedge I to :raise it` up or down to 'adjust the cutting point of the` cutter e; g, a set-.screw to hold the cutter in its place when properly adjusted. Therefore the cutter and its wedge I, being set in the position denoted in black, if it is desirable to throw the Vcutting point back, release the set-screw g, force down the wedge I, as denoted in red, which will force the cutter back, as also denoted in red, or a reverse operation will bring, the cutting point farther forward; thusitbe cutter may be adjusted'with the greatest ease without changing its form or moving it from the machine. In tlie lever E I show a similar adjustment of the cutter c. The cutter is placed between two plates, f and f, and upon one; side a set-screw, t', and upon thcother a similar -set-screw, m, moves the cutter to the right or left, as may be required to adjust the cutting position 'of the cutter e. The upper end of the cutter is retained in the positioni shown in the drawing, so that the adjustment" of the screws z' and m operate only upon the edge of the cutter.

The cutter is-adjusted to diiierent diameters by the setscrew b, in like manner as 'before described.

I have Vrepresented-my improvement as applied to the one class of screw-cutting machines described, yet I do not wish to be understood as limiting myself to this one class, as the same adjustment may be ari inged in thc cutter holders of all screw-cutting machines. l

Having', therefore, thus fully described my invention, what I claim as new and useful, and desire to secure by Letters Patent, lis- The combination of the lever E, the wedge I, cutter e, and set-screws g and c, so as to operate substantially in the manner hereinset forth.`

. E. D. BARRIEIT'I` Witnesses: 1

JOHN E. EARLB, AL'rsIn J. TIBBITs. 

